The present invention relates to a structure for integrally holding a plurality of optical fibers.
Generally, in various devices and modules for optical communication, there is such a case that a plurality of long optical fibers have to be collectively housed in a device.
In order to hold such a plurality of optical fibers in one bundle, conventionally, a process of taking up each of the optical fibers by a reel or routing the optical fibers in a casing is performed.
To hold a plurality of optical fibers in one bundle, there is another case that an optical fiber ribbon is used. The optical fiber ribbon is obtained by arranging a plurality of optical fibers in parallel, covering the optical fibers with a resin, and forming the optical fibers in a rectangular ribbon shape in cross section. This optical fiber ribbon is characterized in that, due to its rectangular shape in cross section, it cannot be bent in the lateral direction (direction in which the optical fibers are arranged in parallel). Conventionally, therefore, by separating the optical fiber ribbon into single optical fibers and routing the optical fibers, housing of the optical fibers is facilitated.
The conventional structure for holding optical fibers housed in such a manner has, however, the problems as follows.
In the case of using a reel, to prevent occurrence of a loss caused by the housing, it is necessary to take up the optical fibers orderly around the reel. Consequently, it takes time and effort to take up the optical fibers.
In the case of routing the optical fibers in a device, a work has to be done while being paid attention so as not to cause entanglement or breaking of the optical fibers, so that it takes time and effort for housing.
In the case of using an optical fiber ribbon, since it cannot be bent in the lateral direction, it is necessary to separate the optical fiber ribbon into single optical fibers and route each of the optical fibers. Like the case of simply routing the optical fibers mentioned above, it takes time and effort for taking up and housing the optical fibers.
Moreover, in any of the cases, the optical fibers cannot be dealt in a plane, a large housing space is required, and it causes such a problem that the size cannot be sufficiently reduced.
Therefore, an object of the present invention is to facilitate a work of housing a plurality of long optical fibers into a device, reduce a housing space, and accordingly realize a reduced size by enabling the optical fibers to be handled integrally.
According to the present invention, an optical fiber is routed in a plane and sealed with a thin member. With the configuration, optical fibers can be integrally handled without coming apart or getting entangled as a whole and easily disposed in a device. Since the optical fibers are sealed with the thin member, a sheet state is obtained as a whole. Consequently, a small housing space is sufficient and a small size can be achieved. Moreover, the optical fibers are protected by the thin member, an influence such as a damage can be lessened.
The invention can be easily realized by sandwiching the optical fiber by the thin member.
The invention becomes more effective in the case of holding a plurality of optical fibers.
According to the invention, in the improved structure for holding an optical fiber mentioned above, lengths of the plurality of optical fibers are set to required lengths. Consequently, a transfer time difference can be set between optical fibers.
According to the invention, in the improved structure for holding an optical fiber mentioned above, lengths of the plurality of optical fibers are set to the same length. Consequently, the transfer time of the optical fibers becomes the same, and it becomes unnecessary to consider a delay difference among the optical fibers.
According to the invention, in the improved structure for holding an optical fiber mentioned above, an optical fiber in the thin member is provided with a redundancy area for adjusting the length of the optical fiber. Thus, the transfer time difference among the optical fibers can be easily adjusted.
According to the invention, in the improved structure for holding an optical fiber mentioned above, an end part of the optical fiber led from the thin member is covered with a protection tube and this protection tube is held by the thin member. Since the portion of the optical fiber led out from the end of the thin member can be reinforced and protected by the protection tube, breakage of the optical fiber in this portion can be prevented.
In the structure for holding an optical fiber according to the invention, the thin member can be made of, for example, a material whose main component is a resin. Further, the thin member can be made of a material whose flexibility can be controlled. With such a configuration, according to the degree of mounting to a device, the mounting can be facilitated by arbitrarily controlling the flexibility of the thin member.
According to the invention, in the improved structure for holding an optical fiber mentioned above, a connector is attached to an end of an optical fiber led from the thin member to the outside. It makes the connection to another device easy.
According to the invention, in the improved structure for holding an optical fiber above mentioned, an air layer is provided in a portion where the optical fibers cross each other in the thin member. Consequently, when the thin member is bent, the air layer functions as a buffer material so that an excessive bending force can be prevented from being applied to the optical fibers which cross each other.